Study On Hydrodynamic Characteristics Of Column Anti-wave Environment Monitoring Buoy

The development of marine aquaculture is inseparable from the guidance of the hydro-meteorological data of the aquaculture sea area,but it is difficult for the traditional buoy to obtain hydrological data of intact sections of the sea area.The new column anti-wind wave environment monitoring buoy proposed in this paper is a new type of marine data buoy.It is mainly composed of the cabin,the floating system,the counterweight and the anchor ropes.To achieve different depth of water quality monitoring,it collects water samples through the floating frame,also can be used for environmental monitoring of marine aquaculture area.Since the buoy of this structure is still in its infancy,the stability and safety performance in a complex marine environment have yet to be studied.Therefore,the hydrodynamic characteristics of this kind of column buoy under the effect of water flow and wave are studied in this paper.In this paper,firstly,using the model test method,according to the wave conditions in the East China Sea and the existing prototype of the buoy,the appropriate similarity criteria and scales were selected to study the towing resistance characteristics of the buoy model in still water and the column buoy's motion response characteristics test under different wave conditions.Handling and analysis of towing resistance test data,fitting the expression of the relationship between speed and water resistance,forecasting the prototype resistance at different speeds,and providing guidance for towing operations.The effects of wave height and wave period on the hydrodynamic characteristics of the buoy such as roll,pitch,swinging angle and anchor rope tension were analyzed,and the hydrodynamic quantitative characteristics of the buoys under different wave elements were obtained.The results show that the buoy movement trajectory under the tethering action of the three-way anchor rope is less affected by the wave height,and the amplitude of the vertical movement decreases with the increase of the wave period.The maximum tension of the wave-facing anchor rope is less affected by the wave height,but decreases with the increase of the wave period.Then,the wave hydrodynamic numerical model of the column buoy was established by the finite element method and the concentrated mass point method,and the track trajectory and anchor rope tension were preliminarily verified.The verification results were good and a new method for studying the hydrodynamic characteristic of the column buoy was provided.Through the establishment of mathematical models,the problems of wave force calculation of buoys,translation and rotation of three-dimensional space,conversion between satellite coordinate system and local coordinate system are mainly solved.The method of increasing the length of the anchor rope unit is proposed to efficiently and accurately solve the problem of how to determine the position of the anchor rope in loose state,thereby solving the motion response of the buoy and the anchor rope tension in the time domain.By analyzing the towing resistance characteristics and the wave hydrodynamic characteristics of the column buoy,it is concluded that it have good adaptability to waves under different wave heights and periods,and the new column buoy structure has good wind-wave resistance.The research results and numerical simulation method can provide reference for the design,manufacture and safety performance evaluation of this floating structure.